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From f64e4275ef7407d5c3eca20436519bbd1f796e40 Mon Sep 17 00:00:00 2001 |
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From: Hans de Goede <hdegoede@redhat.com> |
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Date: Tue, 10 Jan 2023 16:30:28 +0100 |
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Subject: ACPI: Fix selecting wrong ACPI fwnode for the iGPU on some Dell laptops |
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|
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From: Hans de Goede <hdegoede@redhat.com> |
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|
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commit f64e4275ef7407d5c3eca20436519bbd1f796e40 upstream. |
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|
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The Dell Latitude E6430 both with and without the optional NVidia dGPU |
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has a bug in its ACPI tables which is causing Linux to assign the wrong |
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ACPI fwnode / companion to the pci_device for the i915 iGPU. |
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|
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Specifically under the PCI root bridge there are these 2 ACPI Device()s : |
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|
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Scope (_SB.PCI0) |
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{ |
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Device (GFX0) |
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{ |
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Name (_ADR, 0x00020000) // _ADR: Address |
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} |
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|
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... |
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|
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Device (VID) |
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{ |
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Name (_ADR, 0x00020000) // _ADR: Address |
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... |
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|
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Method (_DOS, 1, NotSerialized) // _DOS: Disable Output Switching |
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{ |
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VDP8 = Arg0 |
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VDP1 (One, VDP8) |
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} |
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|
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Method (_DOD, 0, NotSerialized) // _DOD: Display Output Devices |
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{ |
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... |
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} |
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... |
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} |
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} |
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|
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The non-functional GFX0 ACPI device is a problem, because this gets |
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returned as ACPI companion-device by acpi_find_child_device() for the iGPU. |
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|
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This is a long standing problem and the i915 driver does use the ACPI |
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companion for some things, but works fine without it. |
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|
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However since commit 63f534b8bad9 ("ACPI: PCI: Rework acpi_get_pci_dev()") |
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acpi_get_pci_dev() relies on the physical-node pointer in the acpi_device |
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and that is set on the wrong acpi_device because of the wrong |
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acpi_find_child_device() return. This breaks the ACPI video code, |
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leading to non working backlight control in some cases. |
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|
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Add a type.backlight flag, mark ACPI video bus devices with this and make |
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find_child_checks() return a higher score for children with this flag set, |
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so that it picks the right companion-device. |
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|
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Fixes: 63f534b8bad9 ("ACPI: PCI: Rework acpi_get_pci_dev()") |
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Co-developed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
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Signed-off-by: Hans de Goede <hdegoede@redhat.com> |
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Cc: 6.1+ <stable@vger.kernel.org> # 6.1+ |
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Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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--- |
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drivers/acpi/glue.c | 14 ++++++++++++-- |
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drivers/acpi/scan.c | 7 +++++-- |
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include/acpi/acpi_bus.h | 3 ++- |
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3 files changed, 19 insertions(+), 5 deletions(-) |
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|
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diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c |
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index 204fe94c7e45..a194f30876c5 100644 |
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--- a/drivers/acpi/glue.c |
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+++ b/drivers/acpi/glue.c |
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@@ -75,7 +75,8 @@ static struct acpi_bus_type *acpi_get_bus_type(struct device *dev) |
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} |
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|
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#define FIND_CHILD_MIN_SCORE 1 |
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-#define FIND_CHILD_MAX_SCORE 2 |
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+#define FIND_CHILD_MID_SCORE 2 |
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+#define FIND_CHILD_MAX_SCORE 3 |
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|
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static int match_any(struct acpi_device *adev, void *not_used) |
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{ |
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@@ -96,8 +97,17 @@ static int find_child_checks(struct acpi_device *adev, bool check_children) |
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return -ENODEV; |
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|
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status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta); |
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- if (status == AE_NOT_FOUND) |
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+ if (status == AE_NOT_FOUND) { |
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+ /* |
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+ * Special case: backlight device objects without _STA are |
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+ * preferred to other objects with the same _ADR value, because |
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+ * it is more likely that they are actually useful. |
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+ */ |
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+ if (adev->pnp.type.backlight) |
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+ return FIND_CHILD_MID_SCORE; |
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+ |
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return FIND_CHILD_MIN_SCORE; |
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+ } |
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|
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if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED)) |
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return -ENODEV; |
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diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c |
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index 274344434282..0c6f06abe3f4 100644 |
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--- a/drivers/acpi/scan.c |
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+++ b/drivers/acpi/scan.c |
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@@ -1370,9 +1370,12 @@ static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp, |
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* Some devices don't reliably have _HIDs & _CIDs, so add |
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* synthetic HIDs to make sure drivers can find them. |
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*/ |
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- if (acpi_is_video_device(handle)) |
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+ if (acpi_is_video_device(handle)) { |
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acpi_add_id(pnp, ACPI_VIDEO_HID); |
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- else if (acpi_bay_match(handle)) |
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+ pnp->type.backlight = 1; |
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+ break; |
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+ } |
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+ if (acpi_bay_match(handle)) |
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acpi_add_id(pnp, ACPI_BAY_HID); |
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else if (acpi_dock_match(handle)) |
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acpi_add_id(pnp, ACPI_DOCK_HID); |
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diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h |
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index cd3b75e08ec3..e44be31115a6 100644 |
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--- a/include/acpi/acpi_bus.h |
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+++ b/include/acpi/acpi_bus.h |
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@@ -230,7 +230,8 @@ struct acpi_pnp_type { |
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u32 hardware_id:1; |
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u32 bus_address:1; |
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u32 platform_id:1; |
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- u32 reserved:29; |
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+ u32 backlight:1; |
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+ u32 reserved:28; |
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}; |
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|
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struct acpi_device_pnp { |
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-- |
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2.39.0 |
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